Caption: Pathfinder Plus in-flight over Hawaii on 24th June 2002. This is a solar-powered, unmanned, all-wing aircraft. The photovoltaic (solar) cells on the upper surface of its wing power eight electric motors, which turn the propellers (white). The aircraft, which is a modified version of the original pathfinder flying wing, has a 37 metre wingspan and weighs 317 kilograms. On 6th August 1998 Pathfinder Plus set a new altitude record for propeller-driven aircraft of approximately 24,500 metres. Pathfinder Plus is a prototype for an aircraft that could stay in- flight indefinitely carrying out scientific research and surveillance.